(i) Field of the Invention
The present invention relates to a process for the purification of aqueous solutions of hydrogen peroxide in order to remove cations and organic acids therefrom.
(ii) Description of Related Art
Aqueous hydrogen peroxide has many industrial uses and, in the case of the electronics field, must exhibit a high purity and must therefore be rid of its cations and organic acids.
The methods of purification described to date refer to distillation, treatment on ion exchange resins, as in French Patent Application FR 1 043 082, treatment on exchange resins to which chelating agents are added, in French Patent Application FR 2 624 500 and to a reverse osmosis process, as in U.S. Pat. No. 4,879,043.
However, these methods are not entirely satisfactory for the removal of some impurities such as especially the ferric Fe.sup.+++ or aluminic Al.sup.+++ ions.
The present invention proposes to remedy these disadvantages.